和田河流域水化学特征与地下水补给来源分析

doi:10.13866/j.azr.2024.06.02

摘要/Abstract

摘要：

为研究和田河流域水化学与地下水补给特征，采用SPSS数理统计分析、Piper三线图、Gibbs图解以及氢氧和¹⁴C同位素示踪等方法对不同地貌单元中的水体（井水、坑塘水和河水）进行了水化学组成特征、补给来源和转化关系分析。结果表明：（1）各水体主要起源于南部海拔2000 m以上的中高山区冰雪融水和大气降水。从山区到沙漠区，地下水水化学类型具有较明显的分带特征。不同水体pH值均呈弱碱性，离子之间组分和TDS值差异较大，整体呈坑塘水>井水>河水的规律。少数地下水样点中NO₃^-含量显著异常。（2）砾质平原区地下水大量接受地表河水的垂向脱节型补给。地下水溶解性总固体（TDS）值小，更新速度快，以水岩溶滤控制作用为主，水化学类型多呈SO₄·Cl-Ca·Mg型。（3）细土平原区地下水TDS值变幅大，多为Cl·SO₄-Na型。其中，河间地块内，靠近上游地下水接受地表水及邻区侧向径流补给，¹⁴C年龄小；中下游地区地下水氢氧同位素“氧漂移”现象普遍。分水岭处地下水¹⁴C年龄大，近河岸处年龄小，地下水与河水联系密切。河间地块两侧地下水分别沿东北、西北方向径流，最终排泄于外围沙漠区。研究结果可为和田河流域水资源合理开发利用和生态环境保护提供科学理论依据。

关键词: 水化学, 地下水, 补给来源, 同位素, 和田河流域

Abstract:

The characteristics of hydrochemistry and groundwater recharge in the Hotan River Basin were studied by analyzing the chemical composition of water, primary recharge sources, and mutual transformation of water bodies (wells, ponds, and rivers) in the different geomorphic units. For this, SPSS statistical analysis, Piper diagram, Gibbs diagram, and isotope tracing methods (D, ¹⁸O, and¹⁴C) were used. The results showed that (1) the water bodies mainly originated from the ice- and snow-meltwater and precipitation in the mid and high mountainous areas>2000 m in the south. From the mountains to the desert, the chemical type and salinity of the groundwater showed obvious zonal characteristics. The different water bodies were weakly alkaline, and the ion composition and TDS values varied with the overall order of pond>well>river. The NO₃^- contents of a few groundwater samples were significantly abnormal. (2) the groundwater in the gravel plain area mainly received vertical and disconnected recharge from the surface river water. The groundwater had a fast renewal rate, low salinity, and major water-rock interactions, mainly of the SO₄·Cl-Ca·Mg type. (3) the TDS value of the groundwater in the fine soil plain area varied over an extensive range, mostly of the Cl·SO₄-Na type. In the inter-river block, the groundwater near the upstream received surface water and lateral runoff from the adjacent areas, and the ¹⁴C age was small. “Drift Oxygen” of δD and δ¹⁸O isotopes in the groundwater of the middle and lower reaches could be generally observed. The ¹⁴C age of the groundwater in the watershed was considerable but minuscule near the riverbank. The relation between the groundwater and the river was close. On both sides of the inter-river block, the groundwater runoff flowed along the northeast and northwest directions, respectively, and finally discharged into the peripheral desert area. The research results can provide a theoretical basis for the reasonable development and utilization of water resources and protect the ecology and environment of the Hotan River Basin.

Key words: hydrochemistry, groundwater, recharging source, isotope, Hotan River Basin

李小等, 常亮, 段瑞, 王倩, 张群慧, 杨炳超. 和田河流域水化学特征与地下水补给来源分析[J]. 干旱区研究, 2024, 41(6): 917-927.

LI Xiaodeng, CHANG Liang, DUAN Rui, WANG Qian, ZHANG Qunhui, YANG Bingchao. Analysis of the hydrochemistry characteristics and groundwater recharge sources in the Hotan River Basin, China[J]. Arid Zone Research, 2024, 41(6): 917-927.

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类型	指标	K⁺/(mg·L^-1)	Na⁺/(mg·L^-1)	Ca²⁺/(mg·L^-1)	Mg²⁺/(mg·L^-1)	Cl^-/(mg·L^-1)	SO₄^2-/(mg·L^-1)	HCO₃^-/(mg·L^-1)	NO₃^-/(mg·L^-1)	TDS/(mg·L^-1)	pH
地下水	极差	39.20	689.39	108.77	131.21	1101.43	653.69	572.59	18.49	2681.04	0.57
	最小值	5.66	52.65	39.33	7.55	73.74	105.53	134.30	0.25	381.16	7.59
	最大值	44.86	742.04	148.10	138.76	1175.17	759.22	706.89	18.74	3062.20	8.16
	平均值	19.73	283.87	82.04	64.21	403.08	265.50	351.25	4.57	1299.64	7.90
	标准差	7.74	165.22	33.66	32.03	243.67	134.20	139.56	4.11	587.82	0.17
	变异系数	0.39	0.58	0.41	0.50	0.60	0.51	0.40	0.90	0.45	0.02
坑塘水	极差	61.81	1166.35	205.89	220.80	1522.22	1318.54	383.36	16.41	3851.77	2.13
	最小值	14.82	214.35	19.67	49.42	264.46	236.93	163.60	3.02	1036.91	7.70
	最大值	76.63	1380.70	225.56	270.22	1786.68	1555.47	546.96	19.43	4888.68	9.83
	平均值	53.21	844.05	83.38	154.19	917.45	749.27	361.08	6.39	3028.06	8.53
	标准差	20.72	414.77	77.33	69.00	523.16	479.44	152.65	5.53	1319.11	0.70
	变异系数	0.39	0.49	0.93	0.45	0.57	0.64	0.42	0.87	0.44	0.08
河水	极差	5.05	80.33	28.50	19.48	123.37	73.98	80.58	2.87	366.78	0.46
	最小值	5.30	46.48	50.97	10.22	63.10	79.55	148.95	2.10	338.26	7.77
	最大值	10.35	126.81	79.47	29.70	186.47	153.53	229.53	4.97	705.04	8.23
	平均值	7.03	79.28	62.73	18.08	111.31	120.12	176.51	4.02	491.49	7.98
	标准差	1.75	28.00	10.49	6.47	41.55	25.64	31.75	0.99	123.60	0.16
	变异系数	0.25	0.35	0.17	0.36	0.37	0.21	0.18	0.25	0.25	0.02

类型	指标 /‰	极差 /‰	最小值 /‰	最大值 /‰	平均值 /‰	标准差	变异系数
地下水	δD	27.50	-69.12	-41.62	-55.02	6.37	-0.12
	δ¹⁸O	3.86	-11.31	-7.45	-8.91	1.00	-0.11
	d-excess	13.17	11.88	25.05	16.25	3.07	0.19
坑塘水	δD	44.11	-41.40	2.72	-26.63	15.09	-0.57
	δ¹⁸O	10.13	-6.46	3.67	-2.88	3.71	-1.29
	d-excess	37.26	-26.95	10.30	-3.57	15.01	-4.20
河水	δD	8.71	-51.77	-43.07	-47.15	2.95	-0.06
	δ¹⁸O	1.97	-9.32	-7.34	-8.40	0.74	-0.09
	d-excess	13.32	15.68	29.00	20.05	5.68	0.28

样品编号	井深/m	水位埋深/m	取样高程/m	补给高程/m	δD/‰	δO/‰	d-excess/‰	¹⁴C年龄/aB.P.
G6	130	4.03	1316	1932	－48.92	－7.68	12.55	330
G8	120	4.21	1299	2379	－53.66	－8.32	12.90	2930
G10	80	4.27	1275	2067	－53.88	－8.38	13.16	320
G12	100	3.75	1260	2127	－55.33	－8.57	13.21	9780
G14	75	3.45	1268	2636	－66.02	－9.82	12.54	7290
G25	85	3.13	1315	1929	－53.00	－8.37	13.96	810